On the maximum average degree and the oriented chromatic number of a graph

On the maximum average degree and the oriented chromatic number of a graph

The oriented chromatic number o(H) of an oriented graph H is de ned as the minimum order of an oriented graph H ′ such that H has a homomorphism to H ′. The oriented chromatic number o(G) of an undirected graph G is then de ned as the maximum oriented chromatic number of its orientations. In this paper we study the links between o(G) and mad(G) de ned as the maximum average degree of the subgra...

On the maximum average degree and the incidence chromatic number of a graph

We prove that the incidence chromatic number of every 3-degenerated graph G is at most ∆(G)+ 4. It is known that the incidence chromatic number of every graph G with maximum average degree mad(G) < 3 is at most ∆(G)+3. We show that when ∆(G) ≥ 5, this bound may be decreased to ∆(G) + 2. Moreover, we show that for every graph G with mad(G) < 22/9 (resp. with mad(G) < 16/7 and ∆(G) ≥ 4), this bou...

the impact of portfolio assessment on iranian efl students essay writing: a process-oriented approach

this study was conducted to investigate the impact of portfolio assessment as a process-oriented assessment mechanism on iranian efl students’ english writing and its subskills of focus, elaboration, organization, conventions, and vocabulary. out of ninety juniors majoring in english literature and translation at the university of isfahan, sixty one of them who were at the same level of writing...

On the Maximum Number of Dominating Classes in Graph Coloring

In this paper we investigate the dominating- -color number،  of a graph G. That is the maximum number of color classes that are also dominating when G is colored using colors. We show that where is the join of G and H. This result allows us to construct classes of graphs such that and thus provide some information regarding two questions raised in [1] and [2].  

The Maximum Number of Edges in a Strongly Multiplicative Graph